[PATCH v2 06/18] arm64: kvm: use -fno-jump-tables with clang
From: samitolvanen@google.com (Sami Tolvanen)
Date: 2017-11-16 16:25:32
Also in:
linux-kbuild, lkml
From: samitolvanen@google.com (Sami Tolvanen)
Date: 2017-11-16 16:25:32
Also in:
linux-kbuild, lkml
On Thu, Nov 16, 2017 at 11:46:17AM +0000, Will Deacon wrote:
Can you elaborate a bit more on exactly what you saw failing here, please?
Mark noticed that clang built kernels fail to boot when the kernel starts at EL2: http://lkml.iu.edu/hypermail/linux/kernel/1711.0/02817.html Turns out starting with LLVM r308050, the compiler decides to use a jump table in __init_stage2_translation, and generates code that branches into an EL1 virtual address.
Whilst it's obviously broken to jump to EL1 from EL2 w/o VHE, the commit message is a bit cryptic.
I agree, I'll add a more descriptive commit message for v3. Sami